| Answer | Crossword Clue |
|---|---|
| ASIATICS | About one billion people. |
| ISLAMIC | Like about 1.5 billion people |
| ALLAH | Deity for over one billion people |
| ASIAN | One of about 3 billion |
| EON | Division of about one billion years |
| NEURON | One of about 100 billion in the human brain |
| EON | The Hadean was the first one, ending about 4 billion years ago |
| INNIE | About 90% of people have one |
